Thermionic valve



June; 25, 1929. w R BULL|MQRE 1,718,632

THERMI ONI C VALVE Original Filed July 21, 1925 li etorlted lune 19239.

llh-ll'lED Fi'l ATES tthg PATENT ()Fl 'lfiE.

THERMIONIC VALVE.

hriginul application filed July 21, 1925, Serial No. 45,124, and in Great Britain May 1, 15.725. Divided.

and this application filed July 16, 1927?.

This invention relates to thermionic valves for use in wireless telegruphy and telephony and to the kind in which 011 grid interposed as at controlling device between a. heated file,- nient and an anode.

The object of the present invention is to provide unproven]ents in the construction and method of mounting the el. -ctro1.les or e. thermionic valve to ensure the nuixiuuun poo-- uihle utilization of electron emission and to maintain the electrodes rigidly in position during use and thus prcserre oven intcrspacing ot the electrodes from one another.

Reference will now he made to the nee-tunpunyinp; drawings WlllCl'l illustrate hy wary ot example constructions according to the invention and in which Figure l is a sectional elevation showing one construction,

Figru'e 2 is sectional elevation oi? another construction,

Figure 3 is a plan ot the construction shown in Figure 1, and

mime 4 is 2 bottom plan thereof.

The form illustrntcd in Figures 1., 3 and 4 comprises :1 filament o in the term of a, pointed straight sided arch secured. its ends to corulnctor supports 72 exrenxlino inwardly from the re-entront tuhe or foot c of the vitreous condiner or hull) or the velve, t .o'rid 7. and suede i which in shupe uro con1- i ul with lluttencd sides 71/ nod 1'? FlQllIfiZ-E o and l the coned portions being); disposed in planes parallel to the two inclined portions of the filament 51?. The flattened sides oil: the rched Qjlll'l end unode lie in planes parallel to :1 line hounectin 51' the two points at which the ends ct the liluinents ere connected to their sup ports Fa. l ."ln additional support 7') is sealed into the re-eiuroul luhc w oi o valve end has sliduhlv mounted thereon, a tubular support 0 the upper end of wl'rlch is "forked as shown u t r to provide o. support for the apex oi the tilement (i hleor the hose oi. the wire p is lined one end oi s lent spring 8 the free end oil which is ilorlred and bent inwmrdl towards the wire 19 to engage on either side of the letter beneoth the end of the tubular 111G111- her (7 which is thus arched upwardly to maintainlhe filament in a tent condition.

Figure 2 illustrates an alternative method of supporting the filament. In this construe Serial No. 206,346.

tion the anode 22 is formed in two parts huw ing peripheral flanges which are caused to shut and are secured together by welding or other suitable means and mounted on topports 7' The shape or the anode in cross section is similar to that shown. in l i rures l to 4;. The grid 3 conforms in shupe to the anode and both of these electrodes are mount ed eoncen trically with u filament 1 the upper end out which is supported by nlelnher u. The upper end oi the member to is split into two out uu'dlv flaring lips r1, whose outer ends curve downwardly and which are partially circular in cross section. The lihnnent is seated in these lips 21nd h .d therel liguinst lateral displacement whilst the curiuituro linperted to the wire by the general contour ot the lips '0 assists it to maintain the required shape approximately to the curvotiu'e ot the upp ends of the grid and anode. The momher u slidoblv mounted. over 0. stem o mounted. in the re-entrent tuhe and around which is coiled a spring 7; the upper end of which hears against the lower edge of the member it thus serving; to maintain, the film lnent always in a tent condition.

Instead of splitting:' the sleeve to to 'lorni the lips o the upper end oi": the sleeve may he attoched thereto by welding); or any other suitable means a T-piece of any desired contour in accordunce with the curvature ot' the electrodes. It to he understomh however that the invention is not limited to our bur-- ticuler form of the u'ienioer 76 as. for exemple, a filament support may he made hv lWWFRl lnfI two pieces of: wire in such a manner that a central portion is formed consisting; of two untwisted portions connected at their ends and presenting; an approximately circular or oval shape in plan. The end portions ot the twisted wires are hent downwardly sud cow nected with the upper eiul oil a sleeve siu'rilur to the t shown at u.

llv supporting: the elmtrodes in the inniuer shove descrihed the t"21i1. l11i.4l011 oi" vibration from the exterior of the vitreous container or hull) to the eleetrmles is prevented and the electrodes are preserved in posi tions of correct interspzicing owing to the common support to which each electrode is socured at its apex.

I clai1n:-

1. A thermionic valve comprising at grid,

2. A thermionic vzllve according to claim 1 wherein said seat for engaging the mid por- 10 tion of the filament Comprises two outwardly flaring lips having downwardly curved outer ends, the filament being sented in those lips.

In Witness whereof I aflix my signature.

WV. R. BULLIMORE. 

